Is it a bad idea not to pick a secondary?

I just started a Monk and all I want to do is protect and heal. Is it a bad idea if I dont pick a secondary profession during pre-seer and go on to post-seer without having a secondary profession? I heard that doing it this way allows you to distribute more attribute points to protecting/healing/divine. What are the goods/bads about this?

Yes... it is a rather bad idea, and i'm not even sure if it's possible. Whatever rumor you hear about being capable of distributing more points is a complete lie. The max amount of attribute points you can spend is 200, and whether or not having 3 extra attributes you CAN spend them on in no way effects the best outcome of what can be achieved. A Single Monk will be no stronger than a Mo/E with the same attributes/skills/weapons. Secondary allows you to build onto a build in situations where you might feel like changing/improving your character.

I don't think you can get to post sear without a 2nd proff. if all you want to do is heal just never put any points into any of the skills in your 2nd proff. Problem solved. When i was playing My E/me I never had any points in anything but fire magic and energy storage. I finished the game that way too.

You can go through the game with just one profession, but it would be a silly thing to do.

With a monk I don't think it really matters, since Monks rarely have any use for secondary skills anyway. However, if you're playing PvE you are at least limiting the number of skills you can pick up as you go along.

my second time through the game was with pure warrior character that used no secondary attributes or skills. I actually found this a very strong PvE character for being effective at both tanking and offense during a mission but the PvP applications are much more limited due to the limited skill range.

there's nothing wrong or weak about choosing to ignore your secondary as long as your focus is PvE and not PvP. PvE allows a character to be effective with a more specialised skillset and thus investing much in your secondary class can actually make you weaker unless you plan on using 2 or more of the skills found there. I can see a pure monk being just as useful in a mission as a Mo/Me or Mo/E

I you want to focus on just being a Monk, I'd recommed either a Mesmer (for energy management), Necromancer (for energy management and various utility spells), or Elementalist (for wards). Early in the game, you'll have more than enough time and energy to do something besides healing. Charrs do very little damage, so you'll want to have something to do, so you don't get bored. Necromancer summons, Elementalist nuking, or Mesmer debuffing are useful, fun, and worthy of a skillbar slot or two, at least up until the desert.

my mesmer is Me/nothing and she is extremely strong, with domination 12 illusion 12 inspiration 12 on PVP

Just pick a secondary, and test it out. If you don't like it, don't waste attribute points on it. If you go protection however, ele secondary does help for the wards.

As for that mesmer, you could've been ele primary, redistributed some attributes, and had 10 extra energy. There's no point in "pure" builds, they're useless. Except maybe a pure ranger.